Erie County is a county along the shore of Lake Erie in western New York State. As of the 2020 census, the population was 954,236. The county seat is Buffalo, which makes up about 28% of the county's population. Both the county and Lake Erie were named for the regional Iroquoian language-speaking Erie tribe of Native Americans, who lived in the area before 1654. They were later pushed out by the more powerful Iroquoian nations tribes. The county is part of the Western New York region of the state.

Buffalo is a city in the U.S. state of New York and the seat of Erie County. It lies in Western New York, at the eastern end of Lake Erie, at the head of the Niagara River, on the United States border with Canada. With a population of 278,349 according to the 2020 census, Buffalo is the 2nd largest city in New York state, 1st being New York City, and the 78th largest city in the United States. Buffalo and the city of Niagara Falls together make up the two-county Buffalo–Niagara Falls Metropolitan Statistical Area (MSA), which had an estimated population of 1.2 million in 2020, making it the 49th-largest MSA in the United States.